the new destructive influence which is thrown into the scale, and the
stronger will take its place. Surrounding conditions remaining
unchanged, the new variety (which we may call B)--supposed, for
argument's sake, to be the best adapted for these conditions which can
be got out of the original stock--will remain unchanged, all accidental
deviations from the type becoming at once extinguished, as less fit for
their post than B itself. The tendency of B to persist will grow with
its persistence through successive generations, and it will acquire all
the characters of a new species.

But, on the other hand, if the conditions of life change in any degree,
however slight, B may no longer be that form which is best adapted to
withstand their destructive, and profit by their sustaining, influence;
in which case if it should give rise to a more competent variety (C),
this will take its place and become a new species; and thus, by
'natural selection', the species B and C will be successively derived
from A.

That this most ingenious hypothesis enables us to give a reason for many
apparent anomalies in the distribution of living beings in time and
space, and that it is not contradicted by the main phenomena of life
and organization appear to us to be unquestionable; and so far it must
be admitted to have an immense advantage over any of its predecessors.
But it is quite another matter to affirm absolutely either the truth or
falsehood of Mr. Darwin's views at the present stage of the inquiry.
Goethe has an excellent aphorism defining that state of mind which he
calls 'Thatige Skepsis'a--active doubt. It is doubt which so loves
truth that it neither dares rest in doubting, nor extinguish itself by
unjustified belief; and we commend this state of mind to students of
species, with respect to Mr. Darwin's or any other hypothesis, as to